Can injury prevention efforts go too far? Reflections on some possible implications of Vision Zero for road accident fatalities

The Swedish National Road Administration has launched a long term vision of a road transport system in which nobody is killed or sustains an injury resulting in permanent impairment (Vision Zero). This paper examines some possible implications of Vision Zero for traffic fatalities. The main points of the paper can be summarised as follows: An objective of eliminating traffic deaths can be interpreted as an application of a general principle of minimising mortality. Minimising overall mortality implies that a survival lottery must be introduced, at any rate as long as there is a shortage of organs for transplants. A survival lottery is a scheme in which people are drawn at random to sacrifice their life for the benefit of others. An objective of eliminating a certain cause of death, like traffic accidents, may be so expensive to realise that there is so much less resources available to control other causes of death that general mortality increases. Several analyses of the relationship between income per capita and general mortality based on Norwegian data document a negative relationship between income and mortality. The loss of income that induces an additional statistical death, due to economic inefficiency, is estimated to between 25 and 317 million NOK (3.8–47.5 million US dollars). These estimates are in line with those of most previous studies. No study of the relationship between income and mortality fully satisfies commonly used criteria of causality. However, the balance of evidence suggests that the relationship between income and mortality is a causal one. A hypothetical programme designed to implement Vision Zero for traffic fatalities was developed and its effects on the number of fatalities estimated. Implementing the whole programme could reduce the number of traffic deaths in Norway from about 300 per year to about 90 per year. Applying the lowest estimate of the income loss that induces an additional death (25 million NOK), it was estimated that implementing the entire hypothetical Vision Zero programme would increase general mortality by about 1355. This would lead to a net increase of about 1145 deaths per year (1355 minus 210 prevented traffic deaths). The analyses presented in this paper show that the possibility cannot be ruled out that a massive effort to eliminate traffic deaths would be counterproductive in terms of overall mortality. This possibility must be regarded as a moral dilemma by advocates of Vision Zero, who have invoked the ethical principle that ‘one must always do everything in one's power to prevent death or serious injury’ to justify the vision.